Several types of the device which are adapted to remove material such as snow from surfaces are known in the prior art. For example, U.S. Pat. No. 1,642,895 granted to Robinson et al. discloses a snow removing machine which includes a motor vehicle chassis which has a rotating brush disposed at the front end thereof. A tube runs from the brush to a tank mounted in the rear end of the chassis, and snow from the brush is propelled through the tube pneumatically by the action of a fan contained in the body of the chassis. However, due to the disparate locations of the broom and the fan, the mechanisms which drive the broom and the fan are necessarily complicated, thereby requiring substantial maintenance time and cost. Also, the broom is driven by a gear drive and the fan is driven by a belt drive, which are not the most highly efficient driving mechanisms and which therefore result in reduced power outputs.
Other snow sweeping devices are known which are adapted to be towed behind a vehicle. These devices, such as the SWEEPSTER SMI/Sicard Remanufacture and the SWEEPSTER Model 2900, are self-contained hydrostatic drive devices which include a rotating brush and an airblast to brush and blow snow off of a surface. However, these devices each have the disadvantage, among others, that the vehicle which pulls the device tends to pack down snow under its tires as it goes, thereby making it more difficult for the device to brush and blow all of the snow off of the surface. Also, although the hydrostatic drive devices are very efficient, they are still relatively complicated and involve hydraulic fluid lines which can often rupture and spill fluid on the surface which is being swept. This is particularly undesirable when the surface being swept is an airport runway.
Still other devices are known, such as SWEEPSTER Models 3000/3100 and S3100B, in which a sweeper brush is attached to the front of a vehicle. These devices also may include airblasts attached to the rear or side of the vehicle to blow snow off of a surface in addition to sweeping it off. Because these devices locate a sweeper brush in front of the vehicle, these devices eliminate the problem of the vehicle packing down snow with its tires before the snow is swept. Unfortunately, though, the frontal brush location gives rise to another problem, because the sweeper brush tends to generate a large amount of overspray, i.e. loose snow which is thrown up in front of the vehicle by the sweeper brush, which can at times severely obscure the vision of an operator of the vehicle. In addition, both the brushes and the airblasts on these devices are powered by hydrostatic drives, which again involve the problems of complexity and possible hydraulic line rupture.
Finally, U.S. Pat. No. 3,735,510 granted to Godfrey et al. discloses a device for removing snow which may include a rotary brush mounted on the front of a vehicle and a tube which delivers high pressure air to the underside of the brush. The high pressure air serves to lift snow from a surface being cleared so that the brush can displace the snow from the path of the vehicle. Like the devices above which carry frontal brushes, this device also has the problem of tending to produce a large amount of overspray, especially since the high pressure air breaks up the snow as the brush contacts the snow, which makes it easier for the snow to be thrown up into the air.
In view of the above, it is an object of the present invention to provide an improved power broom assembly which is readily capable of sweeping materials such as snow from surfaces such as airport runways.
A further object of the present invention is to provide a power broom assembly which includes a broom drive system which is relatively powerful and which experiences relatively minimal vibration.
It is a further object of the present invention to provide a power broom assembly which has a relatively high reliability and which is relatively easy to maintain.
It is a further object of the present invention to provide a power broom assembly which does not pack down the material which is being swept before the material can be swept.
It is a further object of the present invention to provide a power broom assembly which produces very little overspray to obscure the vision of an operator of the broom assembly.
Another object of the present invention is to provide a power broom assembly which is capable of selectively displacing material in its path toward either its left or its right side.
The above objects as well as other objects not specifically enumerated are accomplished by a power broom assembly in accordance with the present invention. The power broom assembly of the present invention includes a vehicle, a rotatable broom mounted to the front of the vehicle, and an airblast assembly mounted to the front of the vehicle above the broom to suck up an overspray of material which has been swept up by the broom.
The objects of the invention are also accomplished by a power broom assembly which includes a power driven broom and an airblast assembly including a casing, an impeller of a cross flow blower inside the casing, an inlet in the casing to allow entry of both air and an overspray from a broom of the power broom assembly, at least two outlets in the casing to allow the air and overspray to be blown out of the cross flow blower, and means for selectively opening and closing the casing outlets. The means for selectively opening and closing the casing outlets includes at least two flexible wall portions which are movable radially inwardly and outwardly to substantially change the inner contour of the casing about the cross flow blower to selectively close and open the casing outlets.
The objects of the present invention are further accomplished by a power broom assembly which includes a power driven broom and a drive system for driving the power driven broom which includes first and second transmission units adjacent a central portion of the power broom assembly. The first transmission unit includes an input shaft and two output shafts. A first output shaft is drivingly connected to an airblast assembly of the power broom assembly and the second output shaft is drivingly connected to an input shaft of the second transmission unit. The second transmission unit includes an input shaft drivingly connected to the second output shaft of the first transmission unit and an output shaft drivingly connected to a broom of the power broom assembly. At least the first and second output shafts of the first transmission unit and the input shaft of the second transmission unit are substantially aligned along a single axis.